The RISKS Digest
Volume 1 Issue 6

Friday, 6th September 1985

Forum on Risks to the Public in Computers and Related Systems

ACM Committee on Computers and Public Policy, Peter G. Neumann, moderator

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Joseph Weizenbaum's comments
Dave Parnas
Good Risks and Bad Risks
Dave Brandin
Hot rodding your AT
Dan Bower
Hazards of VDTs and CRTs
Al Friend
crt & non-crt risks
Brint Cooper
The Case of the Broken Buoy
Herb Lin
Matt Bishop

Joseph Weizenbaum's comments <JOSEPH@MIT-XX.ARPA>: sdi]

Dave Parnas <vax-populi!dparnas@nrl-css >
Thu, 5 Sep 85 07:28:56 pdt

Although there is a great deal of truth and wisdom in Weizenbaum's message, I believe that he overlooks the reason that SDI would be destabilizing and another step in the Arms race. It is not because of the stated goals of the program (Reagan's March 1983 speech) but because those goals are not achievable. There would be nothing wrong with rendering ICBMs and other weapons obsolete. On the contrary, everyone should want to see every country, city, and town protected by an impenetrable shield that would free it from the fear of the indiscriminate horror that rained down on Nagasaki and Hiroshima. It is because the SDIO efforts will not lead to technology of that sort, that SDI is the things that Weizenbaum says it is.

I agree with Weizenbaum that we need to seek non-technological solutions. Technology is not likely to provide solutions in a situation where we oppose a power with equally sophisticated technology.

I believe that SDI is one issue where both disarmament and armament supporters could agree. Both sides seek peace through different mechanisms, but neither will find their goals advanced by an untrustworthy “shield”.


Good Risks and Bad Risks

Thu 5 Sep 85 11:40:30-PDT

Peter: I love your material that's being generated and produced, but I note that it seems to weigh overwhelmingly against the computer. Aren't people sending you any GOOD stuff? Like with the aid of a computer, 27 lives were saved, etc.? Like using the new NEC fingerprint computer, they were able to match the Stalker's finger-prints in 3 minutes, etc? Maybe you need a Call for Good News?


Good Risks and Bad Risks

Peter G. Neumann <Neumann@SRI-CSLA.ARPA>
Thu 5 Sep 85 23:32:45-PDT

Today's SF Chronicle had a nice article on “Computer Holds Promise in Diagnosing Heart Disease”, in greatly reducing the number of false negatives. But even there are significant risks. Suppose you or your doctor trusts the computer program more because it indeed has fewer false negatives, and now you produce a false negative. We are back to the case of the woman who killed her daughter and tried to kill herself and her son because the computer program had falsely produced an “incurable” diagnosis. (See the July 85 issue of Software Engineering Notes.)

Well, in the first issue of RISKS I recall saying there has got to be more to this forum than just pointing out negative things. I noted hope from the research community, although one of the agonizing things that we have observed in the ACM Special Interest Group on Software Engineering (SIGSOFT) is the enormous gap between the research community and what is actually being done in practice. For critical systems, the ordinary software development techniques are simply not good enough.

Yes, we should of course point out successes. For example, the Shuttle project has had many — along with its much more visible problems.


Hot rodding your AT

Wed, 4 Sep 85 14:41:38 EDT

In a recent issue of PC Magazine, Peter Norton espoused the idea of substituting a faster clock chip to enhance performance. Now, according to the folk on the Info-IBM PC digest, this may create problems. An off the shelf PC AT is composed of components guaranteed to work to IBM spec, e.g. 6 Mhz. If I increase the clock rate, then the whole rest of the machine has to be up to snuff. If not, a part dies and I pay a nasty repair bill.

Now if I took Mr. Norton's word as gospel, swapped chips and set my PC AT on fire, would he be liable? How about the publisher?

Hazards of VDTs and CRTs

Al Friend, Space and Naval Warfare Systems Command <friend@nrl-csr >
Thu, 5 Sep 85 15:23:05 edt

When evaluating the risks associated with various forms of technology it is sometimes useful to have in hand the available data.

The Food and Drug Administration published a study in 1981:

An Evaluation of Radiation Emission from Video Display Terminals

HHS Publication FDA 81-8153

The ionizing, optical, RF and acoustic radiation from a number of terminals was measured. I will briefly quote some of the conclusions of this study.

For ionizing radiation:


Sufficient research information is available to estimate a range of risks of injury from ionizing radiation exposure. Delayed disease, such as heritable mutation or cancer, usually forms a basis for the estimation, expressed in terms of the instances of the effect per person per unit of radiation (rad,rem, or R). The risk estimates form a basis for radiation protection guidelines.

 For a VDT operator, the radiation protection guideline for    individuals in the general population is appropriate.  The guideline  — 500 millirem per year — is for man-made radiation exposures  excluding medical use.  For both normal and Phase III operating  conditions, the likely emission from a VDT is 0.1 mR per hour or less.  Terminals capable of exceeding the 0.5 mR per hour regulatory limit  receive special attention (see Section 3.2, above).  With assumptions  of 6 hours of viewing per day, 5 days per week for 50 weeks per year,  the annual radiation dose to an individual 2 inches from the front  surface of a screen emitting 0.1 mR per hour would be 150 millirem.  Note that 2 inches is an unrealistically short viewing distance; as  one moves further away from the screen, the radiation exposure  decreases correspondingly.

  For RF radiation:


  Research information on bioeffects for the frequency range 15kHz to  125 kHz is lacking, so empirical estimates of injury are not possible.  However, the radiation in this frequency region interacts only  slightly with the human body, so that significant biological effects  are unlikely.  At the present time, no standard or guideline has been  adopted in the U.S. for grequencies below 10 MHz.

For ultrasound radiation:


  When airborne ultrasound impinges on human skin less than 1 percent  is absorbed, the remainder being reflected.  The ear, however, is an  efficient coupler of acoustic energy from air into the human body.  Therefore, investigations of the biological effects of ultrasound  levels much higher than those found in the VDT survey have included  temporary threshold shifts in hearing (6).  So-called subjective  effects have also been associated with high levels of ultrasound  exposure, and include fatigue, headache, tinnitis, instability, a  “fullness” in the ear, and nausea.  One report (7) tentatively  associates the subjective effects with audible high frequency  components of sonic radiation.  The studies were performed in the  exposure range 70-120 dB in an industrial setting, and at 150 dB.  No long term effects or delayed injuries are known.

  No formal standard for ultrasound exposure presently exists in the  U.S.  Among several voluntary guidelines available, the   recommendations of W.I. Acton of the United Kingdom were used to  compare the VDT results, because they are the most conservative in  this frequency range.  The highest acoustic measurement obtained  from a VDT in this study was 68 dB, well below Acton's guideline  of 75 dB, and well below the energies associated with biological  effects.

For “ergonomic” factors:



  The word processing field has expanded much faster than has the  understanding of its impact on people who use VDTs.  The impact  may be felt in areas such as employee morale, compensation,  work hours, and work conditions.  We suggest that work conditions  be given serious conisideration as the primary cause of VDT-user  complaints.  The problem is not simple, however.  An extensive  review of stress factors in the word processing work area (10)  identified five separate factors that contribute to fatigue:  vision, posture, environment, task organization, and higher  order items such as disease susceptibility.  As early as 1976,  it was recognized that glare (room lighting reflecting from the  VDT face plate), work position, ambient noise, and work duration  (absence of breaks) could be the most important factors  influencing the VDT worker's health (11).  The parallel  between the 1976 and 1979 studies is sufficiently strong for  us to suggest that efforts expended to reduce stress caused  by these factors would also reduce the adverse impact on  health.

The above quotes from the FDA document are some of its most importantconclusions.  References to additional work are provided in thedocument.  There has been further work since the time of this report(1981).  I do not have immediate access to these later references.  Ibelieve they tend to bear out the conclusions of this report.

From conversations with those closer to this field than I, I get theimpression that one of the major stress factors in commercial wordprocessing operations is the highly regimented work situation, and thepossibility of being fired, if the operator does not turn out a certainminimum amount of mistake free work per hour.

Re:  crt & non-crt risks

Brint Cooper <abc@BRL.ARPA>
Thu, 5 Sep 85 11:55:42 EDT

Many of the crt/workplace issues you raise are shared by another groupwhose members are quite diverse in their use of crt terminals:secretaries. 

I know this is not quite the correct forum, but workplace rules andlegislation designed to "protect" users of terminals from problems ofposture, vision, and stress should consider this forgotten group ofworkers as well.  Their problems are nearly the same.


The Case of the Broken Buoy

Thu,  5 Sep 85 17:06:21 EDT

In response to:

       Dave Curry's right. I remember reading a newspaper report which    said, in essence, that the NWS/NOAA lost because it had failed to    predict the storm.  I didn't believe it, so I read on, and the report    said that since they had known of a broken buoy, had failed to repair    it (I think it had been broken for several months), and therefore failed    to get the information needed to give a warning, they were guilty of    negligence and had to pay.  Quite a far cry from what the story had    begun as!

On the other hand, the NWS also said that even if the buoy had beenalive at the time, they would not have predicted the storm.  Thisisn't to defend sloppy journalism, just to point out that thenewspaper was in essence correct in this instance.

 Re: The Case of the Broken Buoy

Matt Bishop <mab@riacs.ARPAo>
5 Sep 1985 2049-PDT (Thursday)

Did the NWS say that (i.e., even if the buoy had been alive at the time,they could not have predicted the storm) in testimony, or after the verdict?If after the verdict, no comment.  But if as testimony, Herb, the jury (orjudge) apparently didn't believe the NWS testimony.  If you believe the NWSclaim, the headline was correct, but it's unfair to say the court ruled thatway when it explicitly based its ruling on negligence.

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